Question 548661
According to <a href="http://www.mayoclinic.com/health/heart-rate/AN01906">this page</a>, "For an adult, a normal resting heart rate ranges from 60 to 100 beats a minute"



So let's average the endpoints to get 80 beats per minute.



Now convert 270 seconds to minutes by dividing it by 60 to get 270/60 = 4.5 minutes



Finally, multiply that answer by 80 (our assumed average) to get 4.5*80 = 360



So this average adult with a heart rate of 80 beats per minute has his/her heart beat 360 times in 270 seconds